Various machines and methods have been employed to strengthen and finish metal work pieces such as crankshafts and camshafts for internal combustion engines. In many modern vehicles, engines have been downsized and, with the downsizing of vehicles and their components for reducing weight and improving fuel efficiency, smaller engines and crankshafts are often used. To improve the fatigue strength and durability of these crankshafts, deep rolling of fillets and other circular joint areas is increasingly important. The fatigue strength and durability of crank pins and main bearing journals can be significantly increased by deep rolling compressive stresses into the middle of the annular fillets between the pin journals and adjacent counter weights or balancing webs. In previously designed tool mechanisms for deep rolling machines, the burnishing units which hold the working rollers during the deep rolling operation are subjected to significant wear and tear. This wear on a burnishing unit can lead to surface imperfections in a bore of the burnishing unit, which, in turn, can cause loss of hydraulic pressure and improper functioning of the deep rolling tool.